The following are normally used in known technical solutions (1-2). Actuator for the legs of a walking robot, for the most part biped robots, with a mobile element, with a motor located in the mobile element, with a leg base element, which is connected to the mobile element by means of a rotation joint kinematically connected to the motor.
In these solutions the actuator motor along with a constant gear reducing box should compensate the torque produced by the gravitational force. The torque produced by the gravitational force may be compensated for by using small motors with high reduction ratios, but there is also the inconvenience that the speed of the leg is greatly limited. Another possibility is to compensate the torque produced by the gravitational force using big motors with low reduction ratios, but this has the inconvenience that it increases the weight of the robot and the energy consumption thereof.
1. Articulated structure for legged walking robot
Patent Number EP0433096
Publication date 19 Jun. 1991
Inventors: Gomi Hirosi, Kumagai Tomharu,
Hirose Masto, Nishikawa Masao
B25J5/00; B25J11/00; G05D1/10
2. Method and apparatus for dynamic walking control of robot
U.S. Pat. No. 4,834,200                Publication date 30 May 1989        Inventor: Kajita Syuji        B25J5/00; B62D57/02        